Neoadjuvant Radiation Therapy

Quick Summary

Neoadjuvant radiation therapy is the process where radiation for mesothelioma treatment is applied before surgery. This is opposed to the conventional method where radiation is given post-operative. Neoadjuvant radiation helps reduce mesothelioma tumor size making it easier for surgeons to remove cancerous tissue. This helpful treatment also kills cancer cells that could migrate or seed themselves in healthy tissue during surgery.

Neoadjuvant Radiation Therapy Overview

Neoadjuvant radiation therapy is a novel approach to mesothelioma treatment. Radiation is part of a multimodal cancer treatment plan that assists chemotherapy and general surgery. “Adjuvant” comes from the Latin term for “to help” which is what radiation therapy is meant to do. “Neo” refers to “before” or “prior to”.

Combined, the word neoadjuvant summarizes using radiation therapy to help heal the patient before surgery is started and chemotherapy is applied.

Conventional methods for treating pleural and peritoneal mesothelioma dictate that radiation therapy be used after cancerous material is removed from the patient. However, today doctors can administer radiation therapy before surgery in certain situations as part of novel, multimodal therapy.

Using the neoadjuvant radiation therapy approach is part of a 3-step process for treating mesothelioma.

The aim is to stop an aggressive tumor’s spread and control it before surgically removing it. In most cases, radiation is applied externally using high-energy beams targeted at the tumor. Occasionally, internally applied radiation or brachytherapy is involved. This depends on the cell type, tumor size and disease stage. Using neoadjuvant radiation therapy also depends on what the treatment team decides is best for the patient.

What Is Neoadjuvant Radiation Therapy?

Neoadjuvant radiation is not a common procedure. It’s actually a drastic step needed where mesothelioma tumors are large and rapidly spreading.

Neoadjuvant therapy uses large doses of high-energy radiation to stop and shrink a tumor. This makes it easier and more practical for an oncology surgeon to physically cut out cancerous tissue.

Radiation therapy for cancer treatment works on the principle that radiation waves destroy the cancer cells’ DNA. Once a cell’s DNA is essentially scrambled, biological information is no longer passed through the cell giving it instructions to divide and multiply.

In simple terms, cancer is a state where normal cell function of dividing and dying off (apoptosis) no longer happens. Instead, cells keep multiplying and form an aggressive tumor that continues to spread (metastasis).

Neoadjuvant Radiation as Part of Multimodal Treatment

Radiation therapy effectively kills dangerous cells. It’s a proven process, but it’s not independent.

Radiation, by itself, rarely accomplishes solitary treatment. It’s part of a multimodal approach to help control cancer before or after surgery and works effectively with chemotherapy drugs.

Once neoadjuvant radiation therapy begins, surgery becomes inevitable. Sometimes mesothelioma treatment only involves chemotherapy and radiation when the oncology team feels that surgery is impractical or not necessary.

When radiation is applied at the start of treatment, it’s given in high volume, causing the targeted tissue to die. Then, surgeons remove the dead tissue and surrounding tumors.

A normal or typical neoadjuvant radiation therapy process takes 5 days.

Depending on the type of mesothelioma tumor, 1-2 treatment episodes occur each day. Treatment is always externally applied, and the radiation strength depends on the individual case. Surgery follows as soon as possible within a 2-week window.

What Are the Goals of Neoadjuvant Radiation Therapy?

Neoadjuvant radiation therapy has one main goal—using considerable radiation force to stop, shrink or kill a tumor in its tracks.

This is a rather drastic measure and presents hazards to surrounding healthy tissue. However, occasionally oncology teams use neoadjuvant radiation therapy in lesser doses to achieve other goals.

Other neoadjuvant radiation goals may include:

  • Easier to Resect Tumors: Tumors treated with neoadjuvant radiation therapy can be easier to remove that untreated tumor. Often, a tumor is stopped or shrunken during neoadjuvant therapy. Controlled and smaller cancerous tissue is simpler to resect or remove than large active tumors.
  • Prevent Seeding: Seeding happens when cancer cells spread to healthy, unaffected areas. It’s common for active cancer cells to be distributed during a surgical process. This happens when microscopic cancer cells are accidentally spread to incisions and adjacent organs. Here they can take hold or seed and start new tumors. Neoadjuvant radiation therapy can help prevent seeding by prematurely killing these tiny cancer cells.
  • Improve Remission Rates: Successful neoadjuvant radiation therapy helps to lengthen remission rates and shorten recovery time. Applying radiation to mesothelioma tumors before surgery also helps postpone cancer recurrence.
  • Mitigate Damage to Healthy Tissues: Neoadjuvant radiation therapy helps mitigate damage to healthy tissue. Direct radiation exposure to cancerous tissue immobilizes cancer cells and reduces the impact on nearby healthy tissue. This also helps surgeons to remove only what’s necessary and not take out non-cancerous material

Neoadjuvant Radiation Therapy with EPP

Extrapleural pneumonectomy, or EPP, is a surgical procedure commonly used in treating pleural mesothelioma. It involves surgically removing the affected mesothelium lining tissue and one affected lung. This is usually attempted in mid-stage mesothelioma cases when cancer tissue is known to have spread from the lining into the lung.

EPP procedures are ideally suited to using neoadjuvant radiation therapy. The oncology team already forecasts one lung will be sacrificed before the start an EPP intervention.

By applying large doses of radiation pre-operatively, the tumor has a better chance of being stopped and reduced. This amount of radiation is lethal to the lung, which is already intended to be taken out.

Pleural Mesothelioma Treatment Update

An emerging and successful neoadjuvant radiation therapy treatment is called SMART. This stands for Surgery for Mesothelioma After Radiation Therapy. Clinical trials indicate that patients who receive an accelerated neoadjuvant hemithoracic radiation burst immediately before surgery have an improved survival rate.

Neoadjuvant Radiation Therapy with P/D

Pleurectomy with decortication (P/D) is an alternative surgical procedure to EPP and is also used in pleural mesothelioma treatment. With a P/D operation, only the affected mesothelium membrane and a small lung part are removed.

Neoadjuvant radiation is occasionally introduced to P/D practices. Usually, oncologists reserve radiation therapy for post-op or adjuvant treatment.

Neoadjuvant Radiation Therapy with Cytoreduction and HIPEC

Peritoneal mesothelioma treatments sometimes employ a surgical technique called cytoreduction or debulking the mesothelioma tissue. More often now, the surgery team immediately follows tissue removal with a chemotherapy treatment called Heated Intraperitoneal Chemotherapy (HIPEC). This involves using a heated radioactive liquid to wash the abdominal cavity and kill remaining cancer cells.

Possible Side Effects of Neoadjuvant Radiation Therapy

Side effects from neoadjuvant radiation therapy vary from case to case. Often, neoadjuvant patients report the same side effects as adjuvant radiation therapy patients’ experience. Those are usually skin irritation typical of sunburn at the point of radiation entry. Occasionally, patients have physical symptoms similar to having the flu.

Neoadjuvant Radiation Therapy and Survival Rates

Survival rates for mesothelioma patients receiving neoadjuvant radiation therapy are improving as time progresses. Survival rates are similar to those receiving adjuvant radiation treatment, but those can’t be compared on an apples-to-apples base.

Survival rates really depend on the individual patient, what stage their mesothelioma treatment occurred in and the skill of the oncology team.

It’s fair to say that patient survival rates steadily increase as knowledge and techniques for mesothelioma treatment advance.

Seeking Multimodal and Neoadjuvant Radiation Therapy

Today, many mesothelioma treatment centers have the expertise and equipment to really make a difference in patients’ lives. Survival rates continue extending, and palliative symptoms are greatly relieved. This is due to a team approach involving mesothelioma specialists including oncologists, radiologists and assistants.

Mesothelioma patients receiving this type of multimodal and treatment like neoadjuvant radiation therapy have every reason to be optimistic.

For more information on undergoing radiation therapy for mesothelioma, contact our Patient Advocates today.

View Author and Sources
Author

Sources
  1. U.S. National Institute of Health, “Radiation Therapy Options for Malignant Pleural Mesothelioma”, Retrieved from  https://www.ncbi.nlm.nih.gov/pubmed/19822288  Accessed on February 21, 2018
  2. U.S. National Institute of Health, “Novel Approaches in Radiation Therapy for Pleural Mesothelioma”, Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3741784/  Accessed on February 21, 2018
  3. Journal of Nuclear Medicine & Radiation Therapy, “Malignant Pleural Mesothelioma: Role of Radiation Therapy”, Retrieved from https://www.omicsonline.org/malignant-pleural-mesothelioma-management-and-role-of-radiation-therapy-2155-9619.1000S2-011.php?aid=18195  Accessed on February 21, 2018
  4. Mayo Clinic, “Adjuvant Therapy: Keeping Cancer from Returning”, Retrieved from https://www.mayoclinic.org/diseases-conditions/cancer/in-depth/adjuvant-therapy/art-20046687  Accessed on February 21, 2018

Last modified: May 7, 2018